Projected land demands for bioenergy fall well within conservative estimates of current and future land availability (240 to 905 Mha). Estimates for the amount of modern bioenergy needed to meaningfully mitigate climate change range from 80 to 200 EJ in the 2050 timeframe. At the upper end of this range, we estimate
that about 200 million hectares would be required. This may be compared to most estimates for the amount of land available for bioenergy, which exceed 500 million hectares. Long before the world reaches any significant fraction of 200 Mha devoted to modern bioenergy, we will have opportunity to be guided by experience rather than projection. The real danger is not that once the bioenergy genie is out of the
bottle that ruinous land use change will ensue. The recent application of the brakes to bioenergy expansion worldwide provides ample evidence that the growth of bioenergy can be curtailed. Rather, the real danger is that bioenergy development will proceed so slowly that a key strategy for climate change mitigation will be taken off the table. In this chapter we address the questions of whether and how enough biomass could
be produced to make a material contribution to global energy supply on a scale and timeline that is consistent with prominent low carbon energy scenarios. We assess whether bioenergy provision necessarily conflicts with priority ecosystem services including food security for the world’s poor and vulnerable populations.
In order to evaluate the potential land demand for bioenergy, we developed a set of three illustrative scenarios using specified growth rates for each bioenergy sub-sector.